Portable and wireless communication devices have an increased need for security features to restrict use or access of a device to one or more particular users. Speaker recognition has been employed to authenticate a user of such devices. Speaker recognition pertains to recognizing a speaker based on the individual audio information included in an utterance (e.g., speech, voice, or an acoustic signal). Applications of speaker recognition allows the convenient use of the speakers voice for authentication, providing voice-activated dialing, secured banking or shopping, database access, information services, authenticated voice mail, security control for confidential information areas, and controlled remote access to a variety of electronic systems such as computers.
In general, speaker recognition is classified into two broad categories, namely speaker identification and speaker verification. Speaker identification entails determining which registered speaker may have been an author of a particular utterance. On the other hand, speech or speaker verification involves accepting or rejecting the identity claim of a speaker based on the analysis of the particular utterance. In any case, when appropriately deployed, a speaker recognition system converts an utterance, captured by a microphone (e.g., integrated with a portable device such as a wired or wireless phone), into a set of audio indications. The set of audio indications serves as an input to a speech processor to achieve an acceptable understanding of the utterance.
Accurate speech processing of the utterance in a conventional speech or speaker recognition system is a difficult problem, largely because of the many sources of variability associated with the environment of the utterance. For example, a typical speech or speaker recognition system that may perform acceptably in controlled environments, but when used in adverse conditions (e.g., in noisy environments), the performance may deteriorate rather rapidly. This usually happens because noise may contribute to inaccurate speech processing thus compromising reliable identification of the speaker, or alternatively, rejection of imposters in many situations. Thus, while processing speech, a certain level of noise robustness in speech or speaker recognition system may be desirable.